@phillipsc11,
Hmmm... I am not qualified to give legal advice (I don't think anyone can give good legal advice over the internet). I will give my thoughts as a hopefully helpful adult.
1. You should find a counselor, a real adult professional counselor, who can give you real advice. Is there a counselor at your school you can go to? That is where I would start.
2. I don't know anything about this person who is like an uncle to you, it is really difficult for me to judge if he is a responsible person. If he is responsible, you should tell him what you would like.
If a 15 year old came to me with this request, the first thing I would do is find out what the issues were. The second thing I would do is get them counseling or legal support.
3. You have between 2 and 3 years of childhood left. Then you are a legal adult (which means that you will have the legal right to make this decision). You may have to wait... but it is not that long to wait. Be patient; do what you can now to make your life better... and accept the things you can't change right now.
The most important thing is for you to get counseling. They will be able to help you make a plan, and to get legal help if that is what is best.